Posts from Monday, September 20th, 2004

Fractionally Restoring html.css

Published 13 years, 9 months ago

Having talked about how to completely rip away all brower default styles in Firefox, let’s consider the bare minimum of styles we’d need to make the Web at least moderately readable.  As it turns out, the primary factor in document mangling caused by taking out the browser’s default styles is the loss of any display information.  In the absence of information regarding what kind of box an element should generate, they’re all made to generate inline boxes.  This is roughly equivalent to saying:

* {display: inline !important;}

Speaking of which, feel free to try that some time on a test document, or as an entry in a browser’s user style sheet.  The result should remind you of the no-defaults trick.

So let’s say we back up the browser’s default style sheets (you don’t want to lose them completely, unless you plan to re-install the browser) and then erase everything in html.css.  Having done that, we can restore a great deal of sanity to the Web by placing the following rules into html.css.

@namespace url(;
  /* set default namespace to HTML */

html, body, p, div, h1, h2, h3, h4, h5, h6,
ul, ol, dl, dt, dd, blockquote, address, pre,
listing, plaintext, xmp, menu, dir, isindex, hr, map,
multicol, center, frameset, marquee {display: block;}

li {display: list-item;}

area, base, basefont, head, meta, script, style, title,
noembed, noscript, param, noframes {display: none;}

table {display: table;}
caption {display: table-caption;}
tr {display: table-row;}
col {display: table-column;}
colgroup {display: table-column-group;}
tbody {display: table-row-group;}
thead {display: table-header-group;}
tfoot {display: table-footer-group;}
td {display: table-cell;}
th {display: table-cell;}

That rule set will not only cause block-level elements to start generating block boxes again, but it also lets list items be list items, hides the elements we’d like to have vanish, and restores table behavior to table markup.  With those few rules in place, browsing around will be much easier.  It might not be pretty, but it will avoid the extreme wreckage of removing all default styles.

There will still be some notable differences.  For example, paragraphs may now generate a block box, but they aren’t being given margins, so on most sites paragraphs will suddenly not have a “blank line” of separation.  Similarly, heading margins are gone.  Lists don’t have any predefined indentation.  Table cells don’t have default padding, and the “gutter” around page contents has vanished.  Of course, you might see some or all of those things on a site.  If you do, it means that information has been provided by the site’s styles.

In a quick browse of the Web, I found that CNN‘s site was still kind of scrambled by these styles, though certainly not as badly as before.  As an example, a lot of the article sidebars and pictures weren’t floated, which means the float behavior is markup-driven, not CSS-driven.  Why does it matter?  Because in Firefox, align="right" is just a markup hook on which the default style float: right; gets hung.  If that declaration doesn’t appear in the default styles, the markup will have no visible effect.  In other words, no floating.

The home page of The Mozilla Foundation, on the other hand, hung together pretty well, which indicates all of their layout is driven by CSS instead of presentational markup.  This didn’t come as much of a surprise, but it was nice to see.  I was pleased to find that meyerweb’s home page also stayed in decent shape.

So should you add these rules to your style sheets?  Not unless you’re feeling extra-super-mega-paranoid.  The percentage of visitors displaying your site with the default style sheets removed can be safely estimated to very closely approach zero, maybe even touching it.  Besides which, if someone does drop by with all default styles removed, they’ve probably done it on purpose.  If they then send you snarky e-mail about they broke your site that way, feel free to answer them with a polite acknowledgment that they did, indeed, successfully cut their own throat.  It’s not like that’s your problem, any more than you should be bothered that someone “broke” your site with an anarchic user style sheet that suppresses display of lists and paragraphs, or sets all non-replaced elements to use white text on a white background, or whatever.

A more interesting question is whether you should set up a browser to use just those rules as defaults.  I’m giving serious thought to maintaining two copies of Firefox: a normal install, and a development install that’s been hacked to use just the styles I listed before.  It could prove valuable in checking the design assumptions of a work-in-progress, and thus to identify possible weak points in the author styles.  As an example, if I loaded a new design into the development browser and found that lists were completely non-indented, then I’d know I was leaving the list indentation distance up to browser defaults.  At that point, I could decide whether or not that was a good idea.  In some designs, it might be fine, but in others it could be a problem.  Either way, I’d have the chance to consider that question directly, and reach a decision, instead of sailing blindly on, never having thought about it either way.

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